Author Topic: Main bearings  (Read 381 times)

Offline cudabob496

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Main bearings
« on: October 27, 2017 - 10:08:20 pm »
On an older performance engine, can you tell if your main bearings
are getting close to failure/marginal by your normal oil pressure decreasing
over time?
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

Offline 73_Cuda_4_Me

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Re: Main bearings
« Reply #1 on: October 28, 2017 - 08:14:11 am »
You would notice most oil pressure losses with cam bearing wear, but mains will reflect similar wear as the cam bearings (it was normal back in the day to just change out mains, as it is a lot easier to do, and cam bearings weren't touched)... so mains could be in a lot better condition than cam bearings...
1973 Plymouth Cuda BS23H3B567783

R11 V6X EN2
M21 M25 M31 M88 N41 N42
V1X U B41 C56 G37 J54
JY9 A6X9 0 703 501616
E55 D34 BS23 H3B 567783

Offline Aussie Challenger

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Re: Main bearings
« Reply #2 on: November 04, 2017 - 09:51:03 pm »
When mains are on the way out you get a rumble coming from the engine, usually there is no difference in oil pressure until a big end wears from loss of oil then it is time for a tear down.